共查询到20条相似文献，搜索用时 15 毫秒
1.
R. Velusamy 《Resonance》2007,12(12):12-24
Many nuclear models have been put forward since 1932. Among them the collective model proposed by Aage Niels Bohr and Ben
Roy Mottelson and the nuclear shell model proposed by Maria Goeppert Mayer and Johannes Hans D Jensen are the two most successful
models. A number of experimental facts like the existence of magic numbers compiled by Maria Mayer led to the discovery of
the nuclear shell model. The addition of a nuclear spin-orbit coupling force to the mean field of the nucleons successfully
predicted the nuclear magic numbers and many other properties of nuclei.
R Velusamy is the Head of the PG Department of Physics, Ayya Nadar Janaki Ammal College, Sivakasi, Tamilnadu. His current
interests are in quantum dots and wave packet dynamics. 相似文献
2.
Improved cadmium uptake and accumulation in the hyperaccumulator Sedum alfredii: the impact of citric acid and tartaric acid 总被引：2，自引：0，他引：2
Ling-li LU Sheng-ke TIAN Xiao-e YANG Hong-yun PENG Ting-qiang LI 《Journal of Zhejiang University. Science. B》2013,14(2):106-114
The elucidation of a natural strategy for metal hyperaccumulation enables the rational design of technologies for the clean-up of metal-contaminated soils.Organic acid has been suggested to be involved in toxic metallic element tolerance,translocation,and accumulation in plants.The impact of exogenous organic acids on cadmium(Cd) uptake and translocation in the zinc(Zn)/Cd co-hyperaccumulator Sedum alfredii was investigated in the present study.By the addition of organic acids,short-term(2 h) root uptake of 109 Cd increased significantly,and higher 109 Cd contents in roots and shoots were noted 24 h after uptake,when compared to controls.About 85% of the 109 Cd taken up was distributed to the shoots in plants with citric acid(CA) treatments,as compared with 75% within controls.No such effect was observed for tartaric acid(TA).Reduced growth under Cd stress was significantly alleviated by low CA.Long-term application of the two organic acids both resulted in elevated Cd in plants,but the effects varied with exposure time and levels.The results imply that CA may be involved in the processes of Cd uptake,translocation and tolerance in S.alfredii,whereas the impact of TA is mainly on the root uptake of Cd. 相似文献
3.
Automatic segmentation of bladder in CT images 总被引：1，自引：0，他引：1
Segmentation of the bladder in computerized tomography （CT） images is an important step in radiation therapy planning of prostate cancer. We present a new segmentation scheme to automatically delineate the bladder contour in CT images with three major steps. First, we use the mean shift algorithm to obtain a clustered image containing the rough contour of the bladder, which is then extracted in the second step by applying a region-growing algorithm with the initial seed point selected from a line-by-line scanning process. The third step is to refine the bladder contour more accurately using the rolling-ball algorithm. These steps are then extended to segment the bladder volume in a slice-by-slice manner. The obtained results were compared to manual segmentation by radiation oncologists. The average values of sensitivity, specificity, positive predictive value, negative predictive value, and Hausdorffdistance are 86.5%, 96.3%, 90.5%, 96.5%, and 2.8 pixels, respectively. The results show that the bladder can be accurately segmented. 相似文献
4.
在数字化语言实验系统中,由于采用了ATM技术,语音数据以“帧”且以固定速度传输,语音数据传输实时性好,无延时、无断裂,稳定性好,线路简单安全,同时视频点播通过特制的视频HUB,响应速度快、图像质量佳,保证了声像同步,避免了以太网中经常出现的视频点播的缓冲、停顿、马赛克及声像不同步等现象,且负载能力强,系统可靠,比单纯采用以太网络技术语言实验系统,语音、图象传输的质量更优,尤其是对今后ATM技术的发展能够桥接局域网和广域网世界,拓展了语言实验系统的使用． 相似文献
5.
徐祎 《潍坊教育学院学报》2012,25(2):3-6
欧洲中世纪大学的产生没有一个确定的日期,从某种程度上可以说是十字军从阿拉伯人那里带回来的,其形成具有模糊性。中世纪大学的学生来自欧洲各国,国际性的课程涵盖了阿拉伯人保留下来的古希腊哲学、医学和古罗马法学,印度传来的数字计数法,阿拉伯人通过融汇东西方文化创新了神学、代数、平面及立体几何。中世纪大学为了自由,为了守住对于真理的执着,被世俗和教会两方都视为另类而独立存在着。这些都是中世纪大学诞生过程中与生俱来的特征。 相似文献
6.
Providing a wider movement range of virtual camera is an unsolved problem for state-of-the-art image-based rendering system.
In this paper, we present a new image based rendering technology called panoramic mosaics of slit images with depth that can
provide large virtual camera motion region for some scenes. By limiting camera motion to a horizontal plane only, a slit image
with united depth value is used as the rendering element. The panoramic mosaics of slit images with depth are easy to capture,
and the data size is as small as that of panorama. We present here the capturing, construction as well as rendering process
of panoramic slit images mosaic with depth. In addition, we present the join up process of multiple panoramic slit images
mosaic with depth.
Project(69823003) supported by NSFC 相似文献
7.
K Narendran 《Resonance》2001,6(11):34-41
Forest fires have occurred across the globe at various times in the past. The sources of these fires have been both natural
and anthropogenic. Forest areas in North America, South and S E Asia, Australia, Africa and Amazonia are prone to the incidence
of fires regularly. Forest fires occur almost on an annual basis in the deciduous forests of Southern India. However the extent
of these fires depends on various factors such as the frequency of human disturbances and the climate of the region. These
fires are thought to have impacts on the ecology of plants and animals in the region.
K Narendran currently works at the Centre for Ecological Sciences, Indian Institute of Science, Bangalore. He has been intrigued
by the phenomenon of forest fires and is keen on looking at the historical and ecological aspects of forest fires. He is involved
in mapping forest fires in the Mudumalai Wildlife Sanctuary. His major interests lie in ecological applications of remote
sensing and geographical information systems, and would like to work on questions of ecological relevance at the landscape
level. 相似文献
8.
9.
10.
AN IBR METHOD:PANORAMIC MOSAICS OF SLIT IMAGES WITH DEPTH 总被引：1，自引：0，他引：1
ＩＮＴＲＯＤＵＣＴＩＯＮＴｒａｄｉｔｉｏｎａｌｃｏｍｐｕｔｅｒｇｒａｐｈｉｃｓｔｒｙｔｏｇｅｎｅｒａｔｅｒｅａｌｉｓｔｉｃｓｃｅｎｅｖｉｅｗｆｒｏｍａｇｅｏｍｅｔｒｉｃｍｏｄｅｌ.Ｃｏｍｐｕｔｅｒｖｉｓｉｏｎｅｘｔｒａｃｔｇｅｏｍｅｔｒｉｃｍｏｄｅｌｂｙａｎａ ｌｙｚｉｎｇｉｍａｇｅｓｆｒｏｍｔｈｅｒｅａｌｓｃｅｎｅ .Ｃｏｍｂｉｎｉｎｇｔｈｅｍｔｏｇｅｔｈｅｒｇａｖｅｕｓｔｈｅｉｄｅａｏｆｉｍａｇｅ ｂａｓｅｄｒｅｎｄｅｒｉｎｇ (ＩＢＲ ) ,ｗｈｉｃｈｇｅｎｅｒａｔｅｓｒｅａｌｉｓｔｉｃｓｃｅｎｅｖ… 相似文献
11.
宋丽萍 《西安文理学院学报》2002,17(4):6-9
民族国家整合对于印度这样一个多语言、多宗教、多文化的国家来说 ,是国家发展和综合国力提高的一个重要前提。克什米尔具有自己的特殊性 ,因此 ,在目前的情况下 ,采取完全一体化的模式是不符合印度国情的。相反 ,在印度这样一个国家 ,只能采取相互依赖的模式 ,发挥中央和地方的积极性。同时 ,由于印度政党政治在中央地方关系中发挥特殊的作用 ,所以 ,应该注意防止为了党派私利而肆意妄为的行为 ,这对于健康的整合来说是至关重要的 相似文献
12.
以30例胃癌组织和正常组织为研究对象,通过STR-PCR技术,对6号染色体6q24内的ZAC基因两侧的4个STR基因座进行杂合性缺失分析,统计这4个STR基因座在30例标本中的LOH频率,绘制它们的缺失图谱,得到了第4号和25号这两个样本中发生了包含ZAC基因在内的4285651bp的缺失,为进一步分析ZAC基因发生缺失的断裂点和查找ZAC基因表达下调的原因打下基础. 相似文献
13.
Epigallocatechin-3-gallate (EGCG) has shown remarkably anti-cancer activity, with its bioactivity being related to reactive conditions, such as pH and metal ions. The present study investigated the degradation of EGCG and its effect on prostate cancer cell in the presence of Cu2 . EGCG was incubated with prostate cancer cells, 相似文献
14.
蒲小娟 《兰州石化职业技术学院学报》2011,11(2):44-47
上海合作组织成立十年来,在地区安全、能源合作和经贸领域取得了举世瞩目的成就,随着其影响力的不断扩大,扩员问题也被正式提上日程。目前最有可能成为正式成员国的四个观察员国是蒙古、印度、巴基斯坦、伊朗,通过对这四个国家的实际情况和扩员利弊进行的综合分析,笔者认为,目前上海合作组织扩员机制的执行还需谨慎。 相似文献
15.
Michael J. Beatty 《Communication quarterly》2013,61(2):202-217
Although communication apprehension (CA) is often presented as having a major impact on communication related behavior, the extant literature provides neither strong nor direct support for such claims. In the present research (1) behavior was viewed as a single index of disjunctively connected response options including avoidance, withdrawal and anxiety and (2) CA was viewed as a categorical rather than a continuous variable. Results of two separate studies provide direct evidence suggesting that CAs avoid communication if possible and report considerable anxiety when forced to communicate. 相似文献
16.
Parameters selection in gene selection using Gaussian kernel support vector machines by genetic algorithm 总被引：2，自引：0，他引：2
INTRODUCTION Recent techniques based on oligonucleotide or cDNA microarrays allow the expression level of thousands of genes to be monitored in parallel (Golub et al., 1999). A critically important factor for cancer diagnosis and treatment is the reliable prediction of tumor progression. A remarkable advance for mo- lecular biology and for cancer research is cDNA mi- croarray technology. cDNA microarray datasets havea high dimensionality corresponding to the large number of genes monit… 相似文献
17.
本研究以NS5-NS6为引物,扩增真菌同源性序列ssu-rDNA片段,建立广范围真菌检测的方法。用此方法扩增医学主要致病真菌、细菌和人体细胞,结果所有真菌均扩增出一个约310bp的产物,而细菌和人体细胞均扩增阴性,1pg白色假丝酵母菌DNA即可检出。 相似文献
18.
Kathleen B. Rager 《International Journal of Lifelong Education》2013,32(5):447-461
Although self‐directed learning is a common response for many of the 232,090 US men who are diagnosed with prostate cancer each year, very little is known about the nature of the experience for them. Four themes emerged from interviews with 12 prostate cancer patients describing their self‐education efforts in regard to their disease. A qualitative paradigm was used for this study with data collected using a semi‐structured interview protocol. Purposeful sampling technique was employed to identify information‐rich subjects who were within five years of diagnosis and who had used self‐directed learning extensively in coping with their prostate cancer. Using the constant comparative method, four common themes emerged from the analysis of the interviews:
-
Men don’t talk. The participants indicated that men are reluctant to talk about health problems, including prostate cancer.
-
Living with the reality of my situation and my choices. These prostate cancer patients found that they had difficult choices to make in regard to their treatment and that learning about the side effects of their cancer treatments did not prepare them for the reality of actually experiencing them.
-
The struggle with emotions. The men in this study appeared to be very strong in regard to the cognitive aspects of their self‐directed learning in regard to their cancer but to struggle with their emotional responses.
-
Watchful waiting. The men in this study indicated that once having been diagnosed with prostate cancer, the process of dealing with it is never over. Their learning involved coming to terms with this uncertainty.
19.
LIU Ai-jun FURUSATO Bungo RAVINDRANATH Lakshmi CHEN Yong-mei SRIKANTAN Vasanta MCLEOD David G. PETROVICS Gyorgy SRIVASTAVA Shiv 《Journal of Zhejiang University. Science. B》2007,8(12)
Objective: To investigate molecular alterations associating with prostate carcinoma progression and potentially provide information toward more accurate prognosis/diagnosis. Methods: A set of laser captured microdissected (LCM) specimens from 300 prostate cancer (PCa) patients undergoing radical prostatectomy (RP) were defined. Ten patients representing "aggressive" PCa, and 10 representing "non-aggressive" PCa were selected based on prostate-specific antigen (PSA) recurrence,Gleason score, pathological stage and tumor cell differentiation, with matched patient age and race between the two groups.Normal and neoplastic prostate epithelial cells were collected with LCM from frozen tissue slides obtained from the RP specimens.The expressions of a panel of genes, including NPY, PTEN, AR,AMACR, DD3, and GSTP1, were measured by quantitative real-time RT-PCR (TaqMan), and correlation was analyzed with clinicopathological features. Results: The expressions of AMACR and DD3 were consistently up-regulated in cancer cells compared to benign prostate epithelial cells in all PCa patients, whereas GSTP1 expression was down regulated in each patient. NPY, PTEN and AR exhibited a striking difference in their expression patterns between aggressive and non-aggressive PCas (P=0.0203, 0.0284, and 0.0378, respectively, Wilcoxon rank sum test). The lower expression of NPY showed association with "aggressive" PCas based on a larger PCa patient cohort analysis (P=0.0037,univariate generalized linear model (GLM) analysis). Conclusion: Despite widely noted heterogeneous nature of PCa, gene expression alterations of AMACR, DD3, and GSTP1 in LCM-derived PCa epithelial cells suggest for common underlying mechanisms in the initiation of PCa. Lower NPY expression level is significantly associated with more aggressive clinical behavior of PCa; PTEN and AR may have potential in defining PCa with aggressive clinical behavior. Studies along these lines have potential to define PCa-associated gene expression alterations and likely co-regulation of genes/pathways critical in the biology of PCa onset/progression. 相似文献
20.
Ricardo Trumper 《科学教学研究杂志》2006,43(9):879-906
Bearing in mind students' misconceptions about basic concepts in astronomy, the present study conducted a series of constructivist activities aimed at changing future elementary and junior high school teachers' conceptions about the cause of seasonal changes, and several characteristics of the Sun–Earth–Moon relative movements like Moon phases, Sun and Moon eclipses, and others. The activities and results concerning the cause of seasonal changes are reported. Both the experimental class and the control groups improved their grasp of basic astronomy concepts statistically significantly, although the experimental class made the most impressive progress of all. Regarding subjects relevant to this study (seasonal changes), only the experimental class showed a statistically significant improvement, which justifies the constructivist approach. We conclude that in implementing a reform in the science curriculum, the change has to include the subjects taught and also the way they are taught. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 879–906, 2006 相似文献